Imfrovemsot to metallic cartridges



E. MARTIN.

Metallic Cartridge.

Patented July 12, 1870.

WITNES$E5 EDWIN MARTIN, OF SPRINGFIELD, MASSACHUSETTS.

IMPROVEMENT IN METALLIC CARTRIDGES.

Specification forming part of Letters Patent No. 105,348, dated July 12, 1870.

To all whom it may concern:

Be it known that I, EDWIN MARTIN, of Springfield, in the county oi Hampden and State of Massachusetts, have invented a new and useful Improvement in Metallic Oartridges; and I do hereby declare the following, when taken in connection -with-the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the said invention, and which said drawings constitute part of this specification, and represent, in

Figure 1, a plan view of the inside of a cartridge shell with my invention applied. Fig. 2 is a vertical longitudinal section of the same through lineA 15 of Fig. 1. Fig. 3 isa plan View of the base or cone. Fig. 4 is a side elevation of the same. Fig. 5 is a plan viewof another modification of my invention. Fig. 6 is a vertical longitudinal section through line 0 I) of Fig. 5.

My invention relates to that class of metallic cartridges known as ccnterfire cartridges; and it consists in forming a metallic base of sufiiciently hard metal, somewhat conical in form, and having any desirable number of grooves around its periphery set into a pocket or recess in the outside of the head oi the shell, and securing it therein by forcing down the said pocket upon and around the said conical base, by which process the metal is forced into the annular grooves, thus securing the base within the recess. The base maybe made of steel or iron, and upon'the outer or large end is a recess, at the center of which recess is a nipple upon which to place a percussioncap; and a perforation is made through the .base at the center of. the nipple, and into the interior of the shell through the bottom of the pocket; and my invention also consists in reenforcing the interior of the head of the shell with graphite or plumbago, pressed in firmly around the pocket which holds the conical base at the head of the cartridge, for the purpose of strengthening it, and pleventing the gas from blowing through the head of the cartridge when it is exploded.

That others skilled in the art may be able to make and use my invention, I will proceed to describe its construction and the mode of I its operation.

In the drawings, a represents the shell, in the head of which a recess or pocket is formed by forcing in the metal from the outside by means of a proper punch or tool, '1' being the extreme inner base of said recess, and)" the ordinary flange at the head.

Fig. 3 represents a plan view of the outer end of the conical base or, in which 0 is acenter projection or nipple, a perforation, n, at the center of said nipple, communicating with the interior of the shell, as shown in section in Fig. 2. The outer projection ml projects be yond the plane of the center projection or nipple 0, so that the outer part or serves as a guard to prevent the cap, when placed upon the nipple, from being exploded by any accidental blow.

The metallic base in has one or more annular grooves or channels 1' thereon, and is of a. proper form to fit, in a measure, the recess in the head of the shell. The base on is placed within the pocket or recess, and a tool, lniving a cavity in the end, of a corresponding form to the exterior of the pocket or recess r,but a trifle smaller, is forced down upon the inside of the shell, so that the sides of the cavity in the tool are pressed hard against the exterior of the recess 0', so that the metal at the side of the recess all around is forced hard against the metallic base m. This operation forces the metal at the sides of the recess, or a portion ot'it, into the annulargrooves i iirinly, so that the metallic base m cannot, by any ordinary process, be withdrawn from the recess.

This forms a shell which may be loaded and tired as often as desirable.

I strengthen this shell, as well as any 'other having a projection, or a projecting pocket upon the interior of the head of the shell, in the following manner: I prepare graphite, by reducing it to powder, or grinding it, and place a suitable quantity within the shell, and then press it in firmly by means of a suitable tool, having an annular projection upon the end of suflicient face to cover the graphite at c, and force it in tirmly.

Fig. 1 shows a shell having apocket formed as described in Letters Patent granted to me, and dated March 23, A. I). 1869, nnmlwred 88,191, but re-eni'orccd with graphite, as herein described. This method of re-enforcing a ment of graphite,

. the remelting of the same shell gives great strength tothe head of the shell, and forms a most perfect gas-check, as the graphite, after being pressed in, is perfectly hard, and, as heat has no effect upon-itwhatever, it may be fired any number of times without deteriorating in the least.

It is evident that a shell having a metallic base, m, secured therein, as herein described, is operative as a shell, without the re-enforcewhich is represented in black at 0, but this said re-enforcement is a valuable addition, as it renders any shell much more perfect and durable.

Whenever it is desirable to remelt the copper of which shells are made, having agraphite packing, it may be done, and, as heat. will have no effect upon the graphite, it will of itself separate from the molten metal and remain on top, and may be easily removed. This is a great advantage over'the use of different metals in the manufacture of shells, as would form an alloy which injures its ductility in its manufacture into shells again. I am aware that shells have been heretofore Having described my inventibn, what I claim as new, Patent, isy '1. The metallic perforated base m, having the .,nipple. o. thereomxand, 0118150} more and desire to secure by Letters annular grooves, t, when secured within the recess r at the head of the cartridge-shell, as

- described.

2. The re-enforcement of graphite, pressed firmly in at the interior of the head of the cartridge-shell, for the purpose and in. the

manner substantially as described.

' v EDWIN' MARTIN. Witnesses:

T. A. CURTIS. OGDEN GRISWOLD.

made so that they could be fired and reloaded at pleasure; but never to my knowledge has the device herein shown and described been 

